Systems and methods for automatically forwarding electronic mail when the recipient is otherwise unknown

ABSTRACT

Systems and methods for automatically determining if the recipient of electronic mail that is unknown at the receiving server has left a “forwarding address” with a forwarding address server, thereby allowing either the receiving server, the sending server, or the sending user (computer system), or any other party to the communication, to automatically send the electronic mail content to the correct new address. In addition to this automatic “forwarding”, the sending user is notified as to the new electronic mail address so as to allow the sending user to update manually, or automatically, the user&#39;s individual database of electronic mail addresses.

BACKGROUND OF THE INVENTION

[0001] The present invention relates generally to the field ofelectronic mail management systems, and more specifically to new anduseful methods, apparatus and computer programs for automaticallyforwarding electronic mail to an intended recipient when the recipientis otherwise unknown to the receiving entity.

[0002] The national and international packet switched public network,generically referred to as “the Internet” has existed for some time.Although often referred to as a single technological entity, theInternet is represented by a substantial complex of communicationsystems ranging from conventional analog and digital telephone linesthrough fiber optic, microwave and satellite communications links. Thephysical structure of the Internet is logically unified through theestablishment of common information transport protocols, and addressingand resource referencing schemes that allow quite disparate computersystems to communicate both locally and internationally with oneanother.

[0003] Electronic mail over the Internet provides a quick and convenientway for computer users to communicate. This communication is typicallyinitiated by a message sender who composes a message using a textediting program, provides the electronic mail address of the intendedrecipient, and often provides an indication of the content (subjectmatter) of the message by providing text in a “subject” field. Usingwell-understood technology, this composed message is then sent to therecipient's computer address. The recipient's computer receives themessage and stores it in the recipient's inbox. The recipient eventuallyreads, deletes, responds to, or otherwise processes the message storedwithin the inbox by using any of a number of electronic mail programswell known in the art.

[0004] Because such electronic mail messages travel across networks,they generally are constructed according to the Standard for the Formatof ARPA Internet Text Messages specification (RFC822). Thisspecification can be found on the world wide web of the Internet ataddress “http://www.cis.ohio-state.edu/htbin/rfc/rfc822.html”. Messagesformatted to the RFC822 standard have a header portion and an optionalbody portion that contains the text of the message. The header portionincludes a number of fields that address and classify the message. Forexample, the header portion of a message contains fields composed ofcharacter strings comprising a field-name followed by a colon, followedby a field-body terminated with a carriage return/line feed. An exampleheader field is:

[0005] “To: John Doe”. {cr} {lf}

[0006] In this example, the {cr} represents the ASCII carriage returncharacter and the {lf} represents the ASCII line feed character. Theheader field-names are not case sensitive, thus, “to:” is equivalent to“TO:”, “To:” or “tO:”.

[0007] Today electronic mail service is typically provided by anelectronic mail server connected to the Internet. Another dynamicinformation source is provided by independently operating list serversresiding on computer systems that are, in general, connected to theInternet. A list server is typically an automated service that functionsautonomously to repeat electronic mail messages received by apublicly-known list server electronic mail account to an establishedlist of subscribers known to the list server by explicit or fullyqualified electronic mail addresses. The list server is thus anautomated electronic/relectronic mailer that allows a one-to-manydistribution of electronic mail messages through the operation of thelist server. The relectronic mailing of electronic mail messages istypically dynamic and, therefore, persistent messages are maintained, ifat all, selectively by the subscribers of a particular mailing list.Furthermore, the list servers are themselves subject to extremevariability in location and operation since only a publicly availablededicated electronic mail address is required in substance to operate alist server.

[0008] Currently, when electronic mail is sent, it is packaged invarious formats and sent from the sending user's computer system to anelectronic mail server (sending server), via various means of electronictransmission, and a copy is generally retained on the sending machine.The sending server then packages the message into simple mail transferprotocol (SMTP) format, or Interim Mail Access Protocol (IMAP) format,or other electronic mail protocol formats, using Multipurpose InternetMail Extensions (MIME) or Hypertext Markup Language (HTML) or otherformatting protocols, and a connection is attempted with the recipient.

[0009] During this connection, the electronic mail message is sent fromthe sending server to a receiving server associated with the recipientof the message. In order to accept the electronic mail content from thesending server, the receiving server must generally be able to validatethat there is indeed a user name corresponding exactly with theelectronic mail recipient's name. The receiving server thus checks itsdatabase of electronic mail users and validates the electronic mailrecipient's name (the part of the electronic mail address before the @sign). If the recipient's name is not validated, the receiving servergenerally refuses the electronic mail content and returns an errormessage indicating that the recipient is “unknown”. One generalexception to the foregoing is a receiving server which accepts all themail for a domain (“mail-bagging”), in which case only the domain nameis checked and all recipient mail content is accepted, to be validatedat a later time (usually) by another server.

[0010] When the sending server receives the error message stating thatthe recipient is “unknown”, it generally sends a message back to thesending user that the recipient is unknown. This is typically the end ofany automatic electronic mail service session. The sending user mustinterpret the error message (sent in various text and formats) anddecide how to proceed.

[0011] The ability to change electronic mail addresses expediently hasnot kept pace with the rapid expansion of the Internet. As a result,many electronic mail users feel that they cannot leave their existingInternet Service Provider (ISP) because when and if they do, the ISPwill erase their electronic mail name from the electronic mail server.All the mail that would be sent to them at that address would thereforebe returned “user unknown”. It would take many hours to change allmanual and automatic electronic mail addresses from the old address tothe new address. Many of the users who do indeed change ISPs are forcedto retain the old ISP service for several months until they are surethat all of their electronic mail is being sent to the correct address.

SUMMARY OF THE INVENTION

[0012] The present invention provides systems and methods forautomatically determining if the recipient of electronic mail that isunknown at the receiving server has left a “forwarding address” withanother server (the “forwarding listserver”), thereby allowing eitherthe receiving server, the sending server, or the sending user (e.g.,computer system), or any other party to the communication, toautomatically send the electronic mail content to the (new) correctaddress. In addition to this automatic “forwarding”, the sending user isnotified as to the new electronic mail address so as to allow thesending user to update manually, or automatically via specializedsoftware, the user's individual database of electronic mail addresses.No attempt is made to resolve an unknown user name to any of theexisting user names that might be close in spelling. This would be amajor security breach and go against most of the philosophy in theelectronic mail concept.

[0013] The present invention provides that some or all participants inthe electronic mail process (the sending user, the sending server, thereceiving server, the receiving user, and any other participant) areaware that there is an entity, the “forwarding listserver”, which mayhave on file and available to an electronic mail participant, the newaddress for a particular username which is unknown to a receivingserver. This new address is supplied by the electronic mail user who ischanging their electronic mail address (or their employer, or any otherconcerned party) and is organized in a commercially available databaseon the “forwarding listserver”. Alternately, the new address can besupplied by any other entity, such as the user's new ISP after itreceives from the user their previous e-mail address(es).

[0014] The “forwarding listserver” includes the forwarding information(old electronic mail name and new electronic mail name). The “forwardinglistserver” stores each set of data for a period of time, at the end ofwhich the data is either renewed or purged (manually or automatically).Additionally, other forwarding data can be stored, such as a new postalmail address, new phone number, and other items of data. This data couldbe promulgated based on a variety of criteria, or be available to theInternet at large.

[0015] The manipulations performed by a computer, such as a server or ahome or office computer system, in executing computer instructions areoften referred to in terms, such as adding or comparing, that arecommonly associated with mental operations performed by a humanoperator. No such capability of a human operator is necessary in any ofthe operations described herein that form part of the present invention;the operations are machine operations. Useful machines for performingthe operations of the invention include programmed general purposedigital computers or similar devices. In all cases the method ofcomputation is distinguished from the method of operation in operating acomputer. The present invention relates, in part, to method steps foroperating a computer in processing electrical or other (e.g.,mechanical, chemical, optical) physical signals to generate otherdesired physical signals. These steps are those requiring physicalmanipulation of physical quantities. Usually these quantities take theform of electrical or magnetic signals capable of being stored,transferred, combined, compared, and otherwise manipulated. Thesesignals are referred to as bits, values, elements, symbols characters,terms, numbers, or the like. It will be understood by those skilled inthe art that all of these and similar terms are associated with theappropriate physical quantities and are merely convenient labels appliedto these quantities.

[0016] The invention also relates to apparatus for performing theseoperations. This apparatus may be specially constructed for the requiredpurposes or it may comprise a general purpose computer as selectivelyactivated or reconfigured by a computer program stored in a memory. Theprocedures presented herein are not inherently related to a particularcomputer or other apparatus. In particular, various general purposemachines may be used with programs written in accordance with theteachings herein, or it may prove more convenient to construct morespecialized apparatus to perform the operations. The general requiredstructure for a variety of these machines will appear from thedescription below. Additionally, the invention may be embodied in acomputer readable medium encoded with an electronic mail applicationprogram or other application program.

[0017] According to an aspect of the invention, a method is provided forautomatically resending an electronic message originally sent to areceiving user at a first address that is now invalid to a secondaddress for the receiving user, wherein the second address has beenregistered with a forwarding server. The method typically comprises thesteps of sending an electronic message from a first electronic maildomain to the first address at a second electronic mail domain,determining in the second domain that the first address is no longervalid, and automatically sending a query from the second domain to theforwarding server to determine a new address associated with the firstaddress, wherein the forwarding server stores the first address inassociation with the second address. The method also typically includesthe steps of returning the second address to the second domain, andthereafter automatically sending the electronic message to the secondaddress.

[0018] According to another aspect of the invention, a method isprovided for automatically resending an electronic message originallysent to a receiving user at a first address that is now invalid to asecond address for the receiving user, wherein the second address hasbeen registered with a forwarding server. The method typically comprisesthe steps of sending an electronic message from a first electronic maildomain to the first address at a second electronic mail domain,returning a message to the first domain indicating that the firstaddress is no longer valid, and automatically sending a query from thefirst domain to the forwarding server to determine a new addressassociated with the first address, wherein the forwarding server storesthe first address in association with the second address. The methodalso typically includes the steps of returning the second address to thefirst domain, and thereafter automatically sending the electronicmessage to the second address.

[0019] According to yet another aspect of the present invention, amethod is provided for automatically resending an electronic messageoriginally sent to a receiving user at a destination address that is nowinvalid to a new address for the receiving user, wherein the new addresshas been registered with an address server. The method typicallycomprises the steps of creating an electronic message on a computersystem, the electronic message having a first destination address,sending the electronic message to a first server, sending the electronicmessage from the first server to a second server associated with thedestination address, determining in the second server that thedestination address is not valid, and thereafter automatically sending aquery to the address server to determine a new address associated withthe destination address, wherein the address server stores thedestination address in association with the new address. The method alsotypically includes the steps of returning the new address, andthereafter automatically sending the electronic message to the newaddress.

[0020] According to a further aspect of the present invention, anaddress server is provided. The address server typically includes anaddress database for storing old e-mail addresses in association withnew e-mail addresses for registered users. When the address serverreceives a query from an e-mail server requesting a new e-mail addressassociated with an old e-mail address for a first user, if the firstuser is registered with the address server, the server searches thedatabase for the old address and returns the new address for the firstuser to the e-mail server.

[0021] According to yet a further aspect of the invention, an e-mailserver for receiving and sending electronic messages is provided. Thee-mail server is configured to automatically send a request to anaddress server, which stores old e-mail addresses in association withnew e-mail addresses for registered users, when the e-mail serverreceives a first electronic message from a first computer for adestination address that is no longer valid, and wherein the requestrequests a new address associated with the destination address.

[0022] Reference to the remaining portions of the specification,including the drawings and claims, will realize other features andadvantages of the present invention. Further features and advantages ofthe present invention, as well as the structure and operation of variousembodiments of the present invention, are described in detail below withrespect to the accompanying drawings. In the drawings, like referencenumbers indicate identical or functionally similar elements.

BRIEF DESCRIPTION OF THE DRAWINGS

[0023] These and other advantages and features of the present inventionwill become better understood upon consideration of the followingdetailed description of the invention when considered in connection ofthe accompanying drawings, in which like reference numerals designatelike parts throughout the figures thereof, and wherein:

[0024]FIG. 1 illustrates an exemplary computer system for executingelectronic mail programs that embody the invention; and

[0025]FIG. 2 illustrates an exemplary network structure according, tothe present invention.

DESCRIPTION OF THE SPECIFIC EMBODIMENTS

[0026]FIG. 1 illustrates an exemplary computer system 10 for executingelectronic mail (e-mail) programs and other programs that embody theinvention. Computer system 10 includes an Input/Output (“I/O”) bus 20, acentral processing unit (“CPU”) 25 and a memory section 30. I/O bus 20provides a connection to a keyboard 35, a display unit 40, a diskstorage unit 45, a network interface 50, a removable storage 55, aCD-ROM drive unit 60 and numerous other peripheral devices 65, such as amouse, a modem, a scanner, etc. CD-ROM unit 60 reads a CD-ROM mediumthat typically contains programs and data.

[0027]FIG. 2 illustrates an exemplary network structure according to thepresent invention. Local domain 100 (domain 1) is communicably coupledto multiple domains, including domain 200 (domain 2), over the Internet.Local domain 100 includes a computer system 110 (similar to computersystem 10 of FIG. 1) coupled to a modem 120. Modem 120 provides acommunication connection to gateway/router 130. Alternately, computersystem 110 is directly connected to gateway/router 130 over a network,such as a local area network (LAN), wide area network (WAN) or the like.Gateway/router 130 provides an Internet connection, and is connected tolocal e-mail server 140 (domain1.com) and to local domain name server150. Second domain 200 (domain 2) includes a computer system 210connected to second gateway/router 230 and second e-mail server 240(domain2.com) over LAN 220. Gateway router 230 is connected to seconddomain name server 250.

[0028] Forwarding address server 300 is communicably coupled to domain 1and domain 2 over the Internet as shown in FIG. 2. Gateway/router 310and domain name server 320 are optionally provided to add functionalityto forwarding server 300. As shown, forwarding server 300 is preferablylocated in an Internet domain remote from domain 1 and domain 2,however, forwarding server 300 may be located in domain 1 or domain 2.Forwarding server 300 preferably includes a database of new Internetaddresses associated with old addresses for users that have registeredthese addresses with forwarding server 300 either directly orindirectly, for example, through a new ISP. To register with forwardingserver 300, all that is required is that a new address and an oldaddress be provided to forwarding server 300. Forwarding server 300preferably stores new e-mail addresses in a table in association withold addresses, although any data structure as is well known can be used.

[0029] It be apparent to one skilled in the art that FIG. 2 is merely anillustrative example of a network structure for sending, receiving andresending e-mail messages according to the present invention. Any othernetwork structure can be used without departing from the spirit of theinvention. Additionally, it will be apparent to one skilled in the artthat the present invention is not limited to implementation with anyparticular e-mail server software or client software to perform thefunctions disclosed herein.

[0030] Suppose now that a typical user (e.g., user1@domain1.com) usingcomputer system 110 in local domain 100 desires to send an e-mailmessage to another user (e.g., user2@domain2.com) at second domain 200.Using one of many various e-mail software clients, the first usercomposes a message and addresses the message to the intended recipient,user2@domain2.com (as per RFC 821 and RFC 822, as amended).

[0031] In a preferred embodiment of the present invention, the RFC822protocol is used to construct electronic mail messages. The RFC822specification can be found on the world wide web of the Internet ataddress “http://www.cis.ohiostate.edu/htbin/rfc/rfc822.html”, and isincorporated by reference for all purposes. However, the presentinvention does not require the use of the RFC822 standard, so long asthere exists a method to identify essential addressing information andassociated data. This essential information includes, for example,identification of the message recipient(s) and a subject field for themessage.

[0032] The client e-mail software resident on computer system 110packages the message text and/or attachments in proper e-mail format andsends the e-mail message through modem 120 and router/gateway 130 to thee-mail server 140 for local domain 100 (domain1). Alternately, thee-mail message is sent over a network to e-mail server 140. E-mailserver 140 for domain1 queries an Internet Name Service (local hoststable, Internet Domain Name Server 150, or various directory services)to resolve the destination domain name into an IP address, for exampledomain2.com for second domain 200 (domain2). When this is successfullyaccomplished, e-mail server 140 sends the message to the Internet,addressed to the IP address for second domain 200 (e.g., domain2.com),asking for a connection. At this point the message address can begenerally represented as follows: DestinationUsername@DomainName.

[0033] This message goes first to gateway/router 130, which sends themessage to second gateway/router 230 associated with second domain 200through the various connections on the Internet. When secondgateway/router 230 receives the message, it ascertains whether the IPaddress is associated with second domain 200, e.g., whether thedestination e-mail server is located on local area network 220. If so,gateway/router 230 sends the message to e-mail server 240 for seconddomain 200. Generally, e-mail server 240 checks its internal table ofdomain names (the data after the @ sign) to see if it is the properdestination for that e-mail message. If this is true, e-mail server 240checks the destination username (the data before the @ sign) todetermine whether the destination username is included in the internaltable of names (and aliases). If so, e-mail server 240 accepts theconnection from e-mail server 140 and the entire e-mail message (textand/or attachments) is sent from e-mail server 140 and received bye-mail server 240. E-mail server 140 then typically changes the messagestatus (internally) from an “outgoing” status to a “sent” status, ande-mail server 240 typically moves the incoming message (internally) froma temporary storage area to an area (“local mailbox”) for the seconduser's (user2@domain2.com) local retrieval and disposition. The seconduser connects at various times to e-mail server 240 from a computer,such as computer system 210, using one of many e-mail software clients,and retrieves the e-mail message. The message may or may not be copiedto the computer system 210, and may or may not be deleted from thee-mail server 240.

[0034] According to one embodiment, if the destination username is notfound in the internal table of names (and aliases), e-mail server 240sends a message to the sending e-mail server 140 indicating that theaddress is invalid (e.g., the user does not exist). This message isgenerally referred to as a “non-delivery report” (NDR). Sending e-mailserver 140 then generally places this NDR message in User1's mailboxarea as a new message, possibly adding an explanation of the problem andother text, informing User1 that the e-mail could not be delivered dueto the non-existence of the username on the destination e-mail server.At this point, User1 knows only that the e-mail message has not beendelivered. The username for User2 may have been deleted from the list ofusers on the Domain2 e-mail server 240 for any one of many reasons. Anexample of an NDR is an Undeliverable Mail Notification Message (FromRFC 821) as follows:

[0035] S: MAIL FROM

[0036] R: 250 ok

[0037] S: RCPT TO <@HOSTX.ARPA:JOE@HOSTW.ARPA>

[0038] R: 250 ok

[0039] S: DATA

[0040] R: 354 send the mail data, end with.

[0041] S: Date: 23 Oct 81 11:22:33

[0042] S: From: SMTP@HOSTY.ARPA

[0043] S: To: JOE@HOSTW.ARPA

[0044] S: Subject: Mail System Problem

[0045] S:

[0046] S: Sorry JOE, your message to SAM(HOSTZ.ARPA lost.

[0047] S: HOSTZ.ARPA said this:

[0048] S: “550 No Such User”

[0049] S:

[0050] R: 250 ok

[0051] There are some cases where the destination information isincorrect, but the receiving server knows the correct destination. Insuch cases, one of the following replies can be used to allow thesending server to contact the correct destination.

[0052] 251 User not local; will forward to <forward-path>

[0053] This reply indicates that the receiving server knows the user'smailbox is on another host server and indicates the correct forward-pathto use in the future. Note that either the host or user or both may bedifferent. The receiving server generally takes responsibility fordelivering the message.

[0054] 551 User not local; please try <forward-path>

[0055] This reply indicates that the receiving server knows the user'smailbox is on another host server and indicates the correct forward-pathto use. Note that either the host or user or both may be different. Thereceiving server generally refuses to accept mail for this user, and thesending server must either redirect the mail according to theinformation provided or return an error response to the originatinguser.

[0056] According to one embodiment, if the destination username is notfound, receiving e-mail server 240 sends an NDR to sending e-mail server140. Upon receipt of the NDR, sending e-mail server 140 automaticallysends a request to the IP address for the Forwarding server 300, askingfor a new e-mail address that corresponds to the old e-mail address.According to this embodiment, e-mail server 140 is preferably configuredwith the address for forwarding server 300. Forwarding server 300receives the request, which preferably includes the old e-mail address,and checks its database for any new address associated with the olde-mail address. If User2's new e-mail address has been registered withthe forwarding server 300, directly by User2 or through a new ISP, forexample, forwarding server 300 looks up and returns the new address tosending e-mail server 140.

[0057] Sending e-mail server 140 then automatically resends the e-mailmessage destined for user2 to the new address. Alternately, sendinge-mail server 140 causes the e-mail message to be resent, for example bycommunicating the new address to receiving e-mail server 240 or computersystem 110 with an instruction to resend to the new address. In thisexample, upon receipt of the instruction and new address, receivinge-mail server 240 or computer system 110 automatically resends themessage to the new address.

[0058] To register with forwarding server 300, all that is required isthat a new address and an old address be submitted. Forwarding server300 preferably stores new e-mail addresses in a table in associationwith old addresses, although any data structure as is well known can beused. Additionally, any directory databases including X.500, LDAP, orthe like can be used. Thereafter, when a request is received to locate anew address associated with a user's old address, forwarding server 300searches for the old address and returns the associated new address.

[0059] According to another embodiment, when receiving e-mail server 240identifies that the recipient's username (e.g., old address) is unknown,rather than send an NDR, receiving e-mail server 240 itselfautomatically sends a request to the IP address for the forwardingserver 300 asking for a new e-mail address for the recipient thatcorresponds to the old e-mail address. Forwarding server 300 receivesthe request, which preferably includes the old e-mail address, andchecks for any new address in its database associated with the olde-mail address. If User2's new e-mail address has been registered withforwarding server 300, directly or through a new ISP, for example,forwarding server 300 returns the new address to receiving e-mail server240. Receiving e-mail server 240 then automatically resends the e-mailmessage destined for user2 to the new address. Alternately, receivinge-mail server 240 causes the e-mail message to be resent, for example bycommunicating the new address to sending e-mail server 140 or computersystem 110 with an instruction to resend to the new address. In thisexample, upon receipt of the instruction and new address, sending e-mailserver 140 or computer system 110 automatically resends the message tothe new address. If no new address is found, forwarding server 300returns a message to receiving e-mail server 240 indicating this fact.Receiving e-mail server 240 then sends an NDR to sending e-mail server140. Additionally, in one embodiment, receiving e-mail server 240notifies sending e-mail server 140 that forwarding server 300 wasqueried.

[0060] According to another embodiment, if the destination username isnot found, receiving e-mail server 240 sends an NDR to sending e-mailserver 140. Sending e-mail server 140 then forwards the NDR to computersystem 110. Upon receipt of the NDR, computer system 110 automaticallysends a request to the IP address for forwarding server 300, asking fora new e-mail address that corresponds to the old e-mail address.Forwarding server 300 receives the request, which preferably includesthe old e-mail address, and checks for any new address in its databaseassociated with the old e-mail address. If User2's new e-mail addresshas been registered with forwarding server 300, directly or through anew ISP, for example, forwarding server 300 returns the new address tocomputer system 110. Computer system 110 then automatically resends thee-mail message destined for user2 to the new address. Alternately,computer system 110 causes the e-mail message to be resent, for exampleby communicating the new address to sending e-mail server 140 orreceiving e-mail server 240 with an instruction to resend to the newaddress. In this example, upon receipt of the instruction and newaddress, receiving e-mail server 240 or sending e-mail server 140automatically resends the message to the new address.

[0061] According to another embodiment, if the destination username isnot found, receiving e-mail server 240 sends an NDR, and any othercomputer or networking entity on the network that detects the NDRautomatically sends a query to the IP address for forwarding server 300,asking for a new e-mail address that corresponds to the old e-mailaddress. When forwarding server 300 receives the request, whichpreferably includes the old e-mail address, it checks its database forany new address associated with the old e-mail address. If User2's newe-mail address has been registered with forwarding server 300, directlyor through a new ISP, for example, forwarding server 300 returns the newaddress to the requesting entity. The requesting entity thenautomatically resends the message to the new address, or causes themessage to be sent to the new address.

[0062] According to another embodiment, in addition to the automaticresending the e-mail message to the new address, the sending user isnotified by a new e-mail message or other various means as to the newe-mail address for the recipient. The sending user is then able tomanually update their address book with the new address. Alternately,the sending user's e-mail software (or address book, or other referencetable) resident on computer system 110 receives the new address andautomatically updates the address book with the new e-mail address forthe intended recipient (i.e., user2).

[0063] While the invention has been described by way of example and interms of the specific embodiments, it is to be understood that theinvention is not limited to the disclosed embodiments. To the contrary,it is intended to cover various modifications and similar arrangementsas would be apparent to those skilled in the art. For example, althoughthe original e-mail message is sent to a different Internet domain, theoriginal message can be sent to a destination user in the same domain.Further, although it is preferred that server 140 or server 240automatically resends the original message, forwarding address server300 can automatically send the original electronic message to theintended recipient's new address. Additionally, the invention can beintegrated into the e-mail client software on the sender's system, intothe e-mail servers' software, or a separate software application, whichdetects the NDR, queries the forwarding listserver, resends the mail,etc., can reside on the sender's system or any other entity in thenetwork. Therefore, the scope of the appended claims should be accordedthe broadest interpretation so as to encompass all such modificationsand similar arrangements.

What is claimed is:
 1. A method of automatically resending an electronicmessage originally sent to a receiving user at a first address that isnow invalid to a second address for the receiving user, wherein thesecond address has been registered with a forwarding address server, themethod comprising the steps of: sending an electronic message from afirst electronic mail domain to the first address at a second electronicmail domain; determining in the second domain that the first address isno longer valid; automatically sending a query from the second domain tothe forwarding address server to determine a new address associated withthe first address, and wherein the forwarding address server stores thefirst address in association with the second address; returning thesecond address to the second domain; and thereafter automaticallysending the electronic message to the second address.
 2. The method ofclaim 1, the method further including the step of: creating theelectronic message by a sending user using an electronic mail programhaving an address book, the address book including the first address forthe receiving user; and automatically sending a message to the sendinguser, the message including the second address for the receiving user,so that the sending user is able to manually update the address bookwith the second address.
 3. The method of claim 1, the method furtherincluding the step of: creating the electronic message on a computersystem using an electronic mail program having an address book, theaddress book including the first address for the receiving user;automatically sending the second address for the receiving user to thecomputer system; and automatically updating the address book with thesecond address.
 4. The method of claim 1, wherein the forwarding addressserver is located in a third domain.
 5. The method of claim 1, whereinthe second domain includes an e-mail server, and wherein the e-mailserver performs the step of automatically sending the electronic messageto the second address.
 6. The method of claim 1, wherein the firstdomain includes a first e-mail server, wherein the second domainincludes a second e-mail server, the method further including the stepof: sending a message from the second e-mail server to the first e-mailserver, the message including the second address, wherein the firste-mail server thereafter performs the step of automatically sending theelectronic message to the second address.
 7. A method of automaticallyresending an electronic message originally sent to a user at a firstaddress that is now invalid to a second address for the user, whereinthe second address has been registered with a forwarding address server,the method comprising the steps of: sending an electronic message from afirst electronic mail domain to the first address at a second electronicmail domain; returning a message to the first domain indicating that thefirst address is no longer valid; automatically sending a query from thefirst domain to the forwarding address server to determine a new addressassociated with the first address, and wherein the forwarding addressserver stores the first address in association with the second address;returning the second address to the first domain; and thereafterautomatically sending the electronic message to the second address. 8.The method of claim 7, the method further including the step of:creating the electronic message by a sending user using an electronicmail program having an address book, the address book including thefirst address for the receiving user; and automatically sending amessage to the sending user, the message including the second addressfor the receiving user, so that the sending user is able to manuallyupdate the address book with the second address.
 9. The method of claim7, the method further including the step of: creating the electronicmessage on a computer system using an electronic mail program having anaddress book, the address book including the first address for thereceiving user; automatically sending the second address for thereceiving user to the computer system; and automatically updating theaddress book with the second address.
 10. The method of claim 7, whereinthe forwarding address server is located in a third domain.
 11. Themethod of claim 7, wherein the first domain includes an e-mail server,and wherein the e-mail server performs the step of automatically sendingthe electronic message to the second address.
 12. A method ofautomatically resending an electronic message originally sent to areceiving user at a destination address that is now invalid to a newaddress for the receiving user, wherein the new address has beenregistered with an address server, the method comprising the steps of:a) creating an electronic message on a computer system, the electronicmessage having a first destination address; b) sending the electronicmessage to a first server; c) sending the electronic message from thefirst server to a second server associated with the destination address;d) determining in the second server that the destination address is notvalid; and thereafter e) automatically sending a query to the addressserver to determine a new address associated with the destinationaddress, wherein the address server stores the destination address inassociation with the new address; f) returning the new address; andthereafter g) automatically sending the electronic message to the newaddress.
 13. The method of claim 12, further including the step ofsending a first message from the second server to the first serverindicating that the destination address is not valid.
 14. The method ofclaim 13, wherein the first server performs steps e) and g).
 15. Themethod of claim 13, wherein the first server forwards the first messageto the computer system.
 16. The method of claim 12, wherein the secondserver performs steps e) and g).
 17. The method of claim 12, wherein thestep of creating the electronic message includes using a mail program onthe computer system, the mail program having an address book includingthe destination address for the receiving user, the method furtherincluding the step of sending the new address for the receiving user tothe computer system.
 18. The method of claim 17, further including thestep of automatically updating the address book with the new address forthe receiving user.
 19. The method of claim 12, wherein the addressserver is located in a first domain different from said first and secondservers.
 20. An address server having an address database for storingold e-mail addresses in association with new e-mail addresses forregistered users, wherein when the address server receives a query froman e-mail server requesting a new e-mail address associated with an olde-mail address for a first user, if the first user is registered withthe address server, the server searches the database for the old addressand returns the new address for the first user to the e-mail server. 21.An e-mail server for receiving and sending electronic messages, whereinthe e-mail server is configured to automatically send a request to anaddress server, which stores old e-mail addresses in association withnew e-mail addresses for registered users, when the e-mail serverreceives a first electronic message from a first computer for adestination address that is no longer valid, and wherein the requestrequests a new address associated with the destination address.